For Mac OS X we use a standalone application which supports gestures and inking in MacOS version 10.7 and above.
Since version 2.5.5 the software is implemented as an always on launch agent. This allows start up items to be created for all user accounts and, should the gesture software crash, the system will automatically start the process.
Development history can be viewed from the menu bar item and can also be viewed here.
The gesture software can run in a number of modes of operation dependent on your requirements.
Gestures are performed on the touch screen exactly as they are on a multi-touch track-pad. The action associated with each gesture can be defined in the gesture settings dialog. To utilize all available gestures you will need to use a multi-touch touch screen that supports up to 5 touches otherwise you will be restricted to the gestures that relate to the number of stylus supported on the touch screen.
If gestures is handling the system pointer the gesture software disables the driver’s own posting of single touch data into the system and receives all touch from the touch device via the driver’s API interface. If gestures software is quit then touch will revert back to single touch via the driver’s own system interface.
Depending on the gesture configuration, the gesture software posts all gesture and touch data as OS X native touch events, as TUIO touches (and UPDD TUIO server is running) and the UPDD API interface, regardless of whether there is a gesture action being performed, as the gestures are more or less separate from the touches themselves.
If individual gesture processing is not required (you do not require the gesture to trigger any actions for the performed gestures on the touch screen), you can set the gesture to "No action", and applications will still be able to receive the individual gesture and touch data.
There is also a setting to request that touch data is posted into the system as tablet events, allowing a touch device to be used with Inking and other tablet-related features. It only affects mouse events produced by Gestures, though, since in OS X a tablet event is also a mouse event.
Tablet/Pen device inputs supported by the driver/gestures are always passed into the system as tablet events. Pen nib and co-ordinate information bypasses the gesture engine, i.e. is not processed for gesture consideration.
A number of videos have been posted on the web from end uses such as this one here. Mac OS X gestures are described here.